On-demand scheduling request design

ABSTRACT

An on-demand scheduling request (SR) design is disclosed. Such an on-demand or triggered SR operation provides pre-configuration of user equipments (UEs) with triggered SR resources. Base stations may also configure UEs to monitor for a trigger signal within a bit field of control signaling from the base station. Upon detecting the trigger signal within such bit field, the UEs may use the triggered SR resources for transmitting triggered SR requests. Such use of the triggered SR resources may be in response to UEs detected cancelation of other periodic configured SR resources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/337,928, filed Jun. 6, 2021, entitled, “ON-DEMAND SCHEDULING REQUESTDESIGN,” and also claims the benefit of U.S. Provisional PatentApplication No. 63/047,767, entitled, “ON-DEMAND SCHEDULING REQUESTDESIGN,” filed on Jul. 2, 2020, which is expressly incorporated byreference herein in its entirety.

BACKGROUND Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to an on-demand schedulingrequest (SR) design.

Background

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, and the like. These wireless networks may be multiple-accessnetworks capable of supporting multiple users by sharing the availablenetwork resources. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is theradio access network (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).Examples of multiple-access network formats include Code DivisionMultiple Access (CDMA) networks, Time Division Multiple Access (TDMA)networks, Frequency Division Multiple Access (FDMA) networks, OrthogonalFDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.

A wireless communication network may include a number of base stationsor node Bs that can support communication for a number of userequipments (UEs). A UE may communicate with a base station via downlinkand uplink. The downlink (or forward link) refers to the communicationlink from the base station to the UE, and the uplink (or reverse link)refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlinkto a UE and/or may receive data and control information on the uplinkfrom the UE. On the downlink, a transmission from the base station mayencounter interference due to transmissions from neighbor base stationsor from other wireless radio frequency (RF) transmitters. On the uplink,a transmission from the UE may encounter interference from uplinktransmissions of other UEs communicating with the neighbor base stationsor from other wireless RF transmitters. This interference may degradeperformance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, thepossibilities of interference and congested networks grows with more UEsaccessing the long-range wireless communication networks and moreshort-range wireless systems being deployed in communities. Research anddevelopment continue to advance wireless technologies not only to meetthe growing demand for mobile broadband access, but to advance andenhance the user experience with mobile communications.

SUMMARY

In one aspect of the disclosure, a method of wireless communicationincludes receiving, by a user equipment (UE), a configuration messagefrom a serving base station, wherein the configuration messageconfigures a transmission resource for triggered scheduling request (SR)transmission, monitoring, by the UE, for a trigger signal triggeringtransmission of a triggered SR, and transmitting, by the UE, thetriggered SR using the transmission resource in response to detectingthe trigger signal.

In an additional aspect of the disclosure, an apparatus configured forwireless communication includes means for receiving, by a UE, aconfiguration message from a serving base station, wherein theconfiguration message configures a transmission resource for triggeredSR transmission, means for monitoring, by the UE, for a trigger signaltriggering transmission of a triggered SR, and means for transmitting,by the UE, the triggered SR using the transmission resource in responseto detecting the trigger signal.

In an additional aspect of the disclosure, a non-transitorycomputer-readable medium having program code recorded thereon. Theprogram code further includes code to receive, by a UE, a configurationmessage from a serving base station, wherein the configuration messageconfigures a transmission resource for triggered SR transmission, codeto monitor, by the UE, for a trigger signal triggering transmission of atriggered SR, and code to transmit, by the UE, the triggered SR usingthe transmission resource in response to detecting the trigger signal.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes at least oneprocessor, and a memory coupled to the processor. The processor isconfigured to receive, by a UE, a configuration message from a servingbase station, wherein the configuration message configures atransmission resource for triggered SR transmission, to monitor, by theUE, for a trigger signal triggering transmission of a triggered SR, andto transmit, by the UE, the triggered SR using the transmission resourcein response to detecting the trigger signal.

In one aspect of the disclosure, a method of wireless communication at anetwork entity includes transmitting a configuration message to one ormore served UEs, the configuration message configuring a transmissionresource for triggered SR transmission, transmitting a control signalincluding a trigger signal for the triggered SR transmission, andreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.

In an additional aspect of the disclosure, an apparatus configured forwireless communication at a network entity includes means fortransmitting a configuration message to one or more served UEs, theconfiguration message configuring a transmission resource for triggeredSR transmission, means for transmitting a control signal including atrigger signal for the triggered SR transmission, and means forreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.

In an additional aspect of the disclosure, an apparatus for wirelesscommunication at a base station. The apparatus includes at least onememory and at least one processor coupled with the at least one memory.The at least one processor operable to cause the base station totransmit a configuration message to one or more served UEs, theconfiguration message configuring a transmission resource for triggeredSR transmission, transmit a control signal including a trigger signalfor the triggered SR transmission, and receive the triggered SRtransmission from at least one served UEs of the one or more served UEsusing the transmission resource.

In an additional aspect of the disclosure, a non-transitorycomputer-readable medium storing instructions on a base station. Whenexecuted by a processor, the instructions cause the processor to performoperations including transmitting a configuration message to one or moreserved UEs, the configuration message configuring a transmissionresource for triggered SR transmission, transmitting a control signalincluding a trigger signal for the triggered SR transmission, andreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentdisclosure may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wirelesscommunication system.

FIG. 2 is a block diagram illustrating a design of a base station and aUE configured according to one aspect of the present disclosure.

FIG. 3A is a block diagram illustrating example blocks executed by a UEto implement one aspect of the present disclosure.

FIG. 3B is a block diagram illustrating example blocks executed by abase station to implement one aspect of the present disclosure.

FIG. 4 is a block diagram illustrating an NR-U network having UEs incommunication with base station and configured for on-demand ortriggered SR according to aspects of the present disclosure.

FIG. 5 is a block diagram illustrating an NR-U network having UEs incommunication with base station and configured for on-demand ortriggered SR according to aspects of the present disclosure.

FIG. 6 is a block diagram illustrating an example configuration of a UEconfigured according to one aspect of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to limit the scope of the disclosure.Rather, the detailed description includes specific details for thepurpose of providing a thorough understanding of the inventive subjectmatter. It will be apparent to those skilled in the art that thesespecific details are not required in every case and that, in someinstances, well-known structures and components are shown in blockdiagram form for clarity of presentation.

This disclosure relates generally to providing or participating inauthorized shared access between two or more wireless communicationssystems, also referred to as wireless communications networks. Invarious embodiments, the techniques and apparatus may be used forwireless communication networks such as code division multiple access(CDMA) networks, time division multiple access (TDMA) networks,frequency division multiple access (FDMA) networks, orthogonal FDMA(OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks,GSM networks, 5th Generation (5G) or new radio (NR) networks, as well asother communications networks. As described herein, the terms “networks”and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA(E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and thelike. UTRA, E-UTRA, and Global System for Mobile Communications (GSM)are part of universal mobile telecommunication system (UMTS). Inparticular, long term evolution (LTE) is a release of UMTS that usesE-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documentsprovided from an organization named “3rd Generation Partnership Project”(3GPP), and cdma2000 is described in documents from an organizationnamed “3rd Generation Partnership Project 2” (3GPP2). These variousradio technologies and standards are known or are being developed. Forexample, the 3rd Generation Partnership Project (3GPP) is acollaboration between groups of telecommunications associations thataims to define a globally applicable third generation (3G) mobile phonespecification. 3GPP long term evolution (LTE) is a 3GPP project whichwas aimed at improving the universal mobile telecommunications system(UMTS) mobile phone standard. The 3GPP may define specifications for thenext generation of mobile networks, mobile systems, and mobile devices.The present disclosure is concerned with the evolution of wirelesstechnologies from LTE, 4G, 5G, NR, and beyond with shared access towireless spectrum between networks using a collection of new anddifferent radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diversespectrum, and diverse services and devices that may be implemented usingan OFDM-based unified, air interface. In order to achieve these goals,further enhancements to LTE and LTE-A are considered in addition todevelopment of the new radio technology for 5G NR networks. The 5G NRwill be capable of scaling to provide coverage (1) to a massive Internetof things (IoTs) with an ultra-high density (e.g., ˜1M nodes/km²),ultra-low complexity (e.g., ˜10 s of bits/sec), ultra-low energy (e.g.,˜10+ years of battery life), and deep coverage with the capability toreach challenging locations; (2) including mission-critical control withstrong security to safeguard sensitive personal, financial, orclassified information, ultra-high reliability (e.g., ˜0.99.9999%reliability), ultra-low latency (e.g., ˜1 ms), and users with wideranges of mobility or lack thereof; and (3) with enhanced mobilebroadband including extreme high capacity (e.g., ˜10 Tbps/km²), extremedata rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates),and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms withscalable numerology and transmission time interval (TTI); having acommon, flexible framework to efficiently multiplex services andfeatures with a dynamic, low-latency time division duplex(TDD)/frequency division duplex (FDD) design; and with advanced wirelesstechnologies, such as massive multiple input, multiple output (MIMO),robust millimeter wave (mmWave) transmissions, advanced channel coding,and device-centric mobility. Scalability of the numerology in 5G NR,with scaling of subcarrier spacing, may efficiently address operatingdiverse services across diverse spectrum and diverse deployments. Forexample, in various outdoor and macro coverage deployments of less than3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz,for example over 1, 5, 10, 20 MHz, and the like bandwidth. For othervarious outdoor and small cell coverage deployments of TDD greater than3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHzbandwidth. For other various indoor wideband implementations, using aTDD over the unlicensed portion of the 5 GHz band, the subcarrierspacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, forvarious deployments transmitting with mmWave components at a TDD of 28GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz bandwidth.

The scalable numerology of the 5G NR facilitates scalable TTI fordiverse latency and quality of service (QoS) requirements. For example,shorter TTI may be used for low latency and high reliability, whilelonger TTI may be used for higher spectral efficiency. The efficientmultiplexing of long and short TTIs to allow transmissions to start onsymbol boundaries. 5G NR also contemplates a self-contained integratedsubframe design with uplink/downlink scheduling information, data, andacknowledgement in the same subframe. The self-contained integratedsubframe supports communications in unlicensed or contention-basedshared spectrum, adaptive uplink/downlink that may be flexiblyconfigured on a per-cell basis to dynamically switch between uplink anddownlink to meet the current traffic needs.

Various other aspects and features of the disclosure are furtherdescribed below. It should be apparent that the teachings herein may beembodied in a wide variety of forms and that any specific structure,function, or both being disclosed herein is merely representative andnot limiting. Based on the teachings herein one of an ordinary level ofskill in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. For example,a method may be implemented as part of a system, device, apparatus,and/or as instructions stored on a computer readable medium forexecution on a processor or computer. Furthermore, an aspect maycomprise at least one element of a claim.

FIG. 1 is a block diagram illustrating an example of a wirelesscommunications system 100 that supports an on-demand or triggeredscheduling request (SR) in accordance with aspects of the presentdisclosure. Such an on-demand or triggered SR operation providespre-configuration of UEs 115 with triggered SR resources. Base stations105 may also configure UEs 115 to monitor for an trigger signal within abit field of control signaling from base stations 105. Upon detectingthe trigger signal within such bit field, UEs 115 may use the triggeredSR resources for transmitting triggered SR requests. Such use of thetriggered SR resources may be in response to UEs 115 detectedcancelation of other periodic configured SR resources. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A)network, an LTE-A Pro network, or NR network. In some cases, wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, or communications with low-cost and low-complexitydevices.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB orgiga-NodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions from a base station 105to a UE 115. Downlink transmissions may also be referred to as forwardlink transmissions while uplink transmissions may also be referred to asreverse link transmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up a portion of the geographic coverage area 110,and each sector may be associated with a cell. For example, each basestation 105 may provide communication coverage for a macro cell, a smallcell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable and,therefore, provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap, and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different typesof base stations 105 provide coverage for various geographic coverageareas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone (UE 115 a), a personaldigital assistant (PDA), a wearable device (UE 115 d), a tabletcomputer, a laptop computer (UE 115 g), or a personal computer. In someexamples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet-of-things (IoT) device, an Internet-of-everything(IoE) device, an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles (UE 115 e and UE 115 f),meters (UE 115 b and UE 115 c), or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via machine-to-machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples,half-duplex communications may be performed at a reduced peak rate.Other power conservation techniques for UEs 115 include entering a powersaving “deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In other cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and a wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In certain cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105, or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 may facilitate the schedulingof resources for D2D communications. In other cases, D2D communicationsmay be carried out between UEs 115 without the involvement of a basestation 105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1, N2, N3, orother interface). Base stations 105 may communicate with one anotherover backhaul links 134 (e.g., via an X2, Xn, or other interface) eitherdirectly (e.g., directly between base stations 105) or indirectly (e.g.,via core network 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one packet data network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPmultimedia subsystem (IMS), or a packet-switched (PS) streaming service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 megahertz (MHz) to 300gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known asthe ultra-high frequency (UHF) region or decimeter band, since thewavelengths range from approximately one decimeter to one meter inlength. UHF waves may be blocked or redirected by buildings andenvironmental features. However, the waves may penetrate structuressufficiently for a macro cell to provide service to UEs 115 locatedindoors. Transmission of UHF waves may be associated with smallerantennas and shorter range (e.g., less than 100 km) compared totransmission using the smaller frequencies and longer waves of the highfrequency (HF) or very high frequency (VHF) portion of the spectrumbelow 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that may be capable of toleratinginterference from other users.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

Wireless communications system 100 may include operations by differentnetwork operating entities (e.g., network operators), in which eachnetwork operator may share spectrum. In some instances, a networkoperating entity may be configured to use an entirety of a designatedshared spectrum for at least a period of time before another networkoperating entity uses the entirety of the designated shared spectrum fora different period of time. Thus, in order to allow network operatingentities use of the full designated shared spectrum, and in order tomitigate interfering communications between the different networkoperating entities, certain resources (e.g., time) may be partitionedand allocated to the different network operating entities for certaintypes of communication.

For example, a network operating entity may be allocated certain timeresources reserved for exclusive communication by the network operatingentity using the entirety of the shared spectrum. The network operatingentity may also be allocated other time resources where the entity isgiven priority over other network operating entities to communicateusing the shared spectrum. These time resources, prioritized for use bythe network operating entity, may be utilized by other network operatingentities on an opportunistic basis if the prioritized network operatingentity does not utilize the resources. Additional time resources may beallocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resourcesamong different network operating entities may be centrally controlledby a separate entity, autonomously determined by a predefinedarbitration scheme, or dynamically determined based on interactionsbetween wireless nodes of the network operators.

In various implementations, wireless communications system 100 may useboth licensed and unlicensed radio frequency spectrum bands. Forexample, wireless communications system 100 may employ license assistedaccess (LAA), LTE-unlicensed (LTE-U) radio access technology, or NRtechnology in an unlicensed band (NR-U), such as the 5 GHz ISM band. Insome cases, UE 115 and base station 105 of the wireless communicationssystem 100 may operate in a shared radio frequency spectrum band, whichmay include licensed or unlicensed (e.g., contention-based) frequencyspectrum. In an unlicensed frequency portion of the shared radiofrequency spectrum band, UEs 115 or base stations 105 may traditionallyperform a medium-sensing procedure to contend for access to thefrequency spectrum. For example, UE 115 or base station 105 may performa listen before talk (LBT) procedure such as a clear channel assessment(CCA) prior to communicating in order to determine whether the sharedchannel is available.

A CCA may include an energy detection procedure to determine whetherthere are any other active transmissions on the shared channel. Forexample, a device may infer that a change in a received signal strengthindicator (RSSI) of a power meter indicates that a channel is occupied.Specifically, signal power that is concentrated in a certain bandwidthand exceeds a predetermined noise floor may indicate another wirelesstransmitter. A CCA also may include message detection of specificsequences that indicate use of the channel. For example, another devicemay transmit a specific preamble prior to transmitting a data sequence.In some cases, an LBT procedure may include a wireless node adjustingits own backoff window based on the amount of energy detected on achannel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedbackfor its own transmitted packets as a proxy for collisions.

In general, four categories of LBT procedure have been suggested forsensing a shared channel for signals that may indicate the channel isalready occupied. In a first category (CAT 1 LBT), no LBT or CCA isapplied to detect occupancy of the shared channel. A second category(CAT 2 LBT), which may also be referred to as an abbreviated LBT, asingle-shot LBT, or a 25-μs LBT, provides for the node to perform a CCAto detect energy above a predetermined threshold or detect a message orpreamble occupying the shared channel. The CAT 2 LBT performs the CCAwithout using a random back-off operation, which results in itsabbreviated length, relative to the next categories.

A third category (CAT 3 LBT) performs CCA to detect energy or messageson a shared channel, but also uses a random back-off and fixedcontention window. Therefore, when the node initiates the CAT 3 LBT, itperforms a first CCA to detect occupancy of the shared channel. If theshared channel is idle for the duration of the first CCA, the node mayproceed to transmit. However, if the first CCA detects a signaloccupying the shared channel, the node selects a random back-off basedon the fixed contention window size and performs an extended CCA. If theshared channel is detected to be idle during the extended CCA and therandom number has been decremented to 0, then the node may begintransmission on the shared channel. Otherwise, the node decrements therandom number and performs another extended CCA. The node would continueperforming extended CCA until the random number reaches 0. If the randomnumber reaches 0 without any of the extended CCAs detecting channeloccupancy, the node may then transmit on the shared channel. If at anyof the extended CCA, the node detects channel occupancy, the node mayre-select a new random back-off based on the fixed contention windowsize to begin the countdown again.

A fourth category (CAT 4 LBT), which may also be referred to as a fullLBT procedure, performs the CCA with energy or message detection using arandom back-off and variable contention window size. The sequence of CCAdetection proceeds similarly to the process of the CAT 3 LBT, exceptthat the contention window size is variable for the CAT 4 LBT procedure.

Use of a medium-sensing procedure to contend for access to an unlicensedshared spectrum may result in communication inefficiencies. This may beparticularly evident when multiple network operating entities (e.g.,network operators) are attempting to access a shared resource. Inwireless communications system 100, base stations 105 and UEs 115 may beoperated by the same or different network operating entities. In someexamples, an individual base station 105 or UE 115 may be operated bymore than one network operating entity. In other examples, each basestation 105 and UE 115 may be operated by a single network operatingentity. Requiring each base station 105 and UE 115 of different networkoperating entities to contend for shared resources may result inincreased signaling overhead and communication latency.

In some cases, operations in unlicensed bands may be based on a carrieraggregation configuration in conjunction with component carriersoperating in a licensed band (e.g., LAA). Operations in unlicensedspectrum may include downlink transmissions, uplink transmissions,peer-to-peer transmissions, or a combination of these. Duplexing inunlicensed spectrum may be based on frequency division duplexing (FDD),time division duplexing (TDD), or a combination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving device is equipped with one or moreantennas. MIMO communications may employ multipath signal propagation toincrease the spectral efficiency by transmitting or receiving multiplesignals via different spatial layers, which may be referred to asspatial multiplexing. The multiple signals may, for example, betransmitted by the transmitting device via different antennas ordifferent combinations of antennas. Likewise, the multiple signals maybe received by the receiving device via different antennas or differentcombinations of antennas. Each of the multiple signals may be referredto as a separate spatial stream, and may carry bits associated with thesame data stream (e.g., the same codeword) or different data streams.Different spatial layers may be associated with different antenna portsused for channel measurement and reporting. MIMO techniques includesingle-user MIMO (SU-MIMO) where multiple spatial layers are transmittedto the same receiving device, and multiple-user MIMO (MU-MIMO) wheremultiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g. synchronization signals,reference signals, beam selection signals, or other control signals) maybe transmitted by a base station 105 multiple times in differentdirections, which may include a signal being transmitted according todifferent beamforming weight sets associated with different directionsof transmission. Transmissions in different beam directions may be usedto identify (e.g., by the base station 105 or a receiving device, suchas a UE 115) a beam direction for subsequent transmission and/orreception by the base station 105.

Some signals, such as data signals associated with a particularreceiving device, may be transmitted by a base station 105 in a singlebeam direction (e.g., a direction associated with the receiving device,such as a UE 115). In some examples, the beam direction associated withtransmissions along a single beam direction may be determined based atleast in in part on a signal that was transmitted in different beamdirections. For example, a UE 115 may receive one or more of the signalstransmitted by the base station 105 in different directions, and the UE115 may report to the base station 105 an indication of the signal itreceived with a highest signal quality, or an otherwise acceptablesignal quality. Although these techniques are described with referenceto signals transmitted in one or more directions by a base station 105,a UE 115 may employ similar techniques for transmitting signals multipletimes in different directions (e.g., for identifying a beam directionfor subsequent transmission or reception by the UE 115), or transmittinga signal in a single direction (e.g., for transmitting data to areceiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

In certain implementations, the antennas of a base station 105 or UE 115may be located within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In additional cases, UEs 115 and base stations 105 may supportretransmissions of data to increase the likelihood that data is receivedsuccessfully. HARQ feedback is one technique of increasing thelikelihood that data is received correctly over a communication link125. HARQ may include a combination of error detection (e.g., using acyclic redundancy check (CRC)), forward error correction (FEC), andretransmission (e.g., automatic repeat request (ARQ)). HARQ may improvethroughput at the MAC layer in poor radio conditions (e.g.,signal-to-noise conditions). In some cases, a wireless device maysupport same-slot HARQ feedback, where the device may provide HARQfeedback in a specific slot for data received in a previous symbol inthe slot, while in other cases, the device may provide HARQ feedback ina subsequent slot, or according to some other time interval.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases, a subframe may be thesmallest scheduling unit of the wireless communications system 100, andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe or may be dynamically selected (e.g.,in bursts of shortened TTIs (sTTIs) or in selected component carriersusing sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier,” as may be used herein, refers to a set of radiofrequency spectrum resources having a defined physical layer structurefor supporting communications over a communication link 125. Forexample, a carrier of a communication link 125 may include a portion ofa radio frequency spectrum band that is operated according to physicallayer channels for a given radio access technology. Each physical layerchannel may carry user data, control information, or other signaling. Acarrier may be associated with a pre-defined frequency channel (e.g., anevolved universal mobile telecommunication system terrestrial radioaccess (E-UTRA) absolute radio frequency channel number (EARFCN)), andmay be positioned according to a channel raster for discovery by UEs115. Carriers may be downlink or uplink (e.g., in an FDD mode), or beconfigured to carry downlink and uplink communications (e.g., in a TDDmode). In some examples, signal waveforms transmitted over a carrier maybe made up of multiple sub-carriers (e.g., using multi-carriermodulation (MCM) techniques such as orthogonal frequency divisionmultiplexing (OFDM) or discrete Fourier transform spread OFDM(DFT-S-OFDM)).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR).For example, communications over a carrier may be organized according toTTIs or slots, each of which may include user data as well as controlinformation or signaling to support decoding the user data. A carriermay also include dedicated acquisition signaling (e.g., synchronizationsignals or system information, etc.) and control signaling thatcoordinates operation for the carrier. In some examples (e.g., in acarrier aggregation configuration), a carrier may also have acquisitionsignaling or control signaling that coordinates operations for othercarriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth, or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs 115 that support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

Wireless communications system 100 may support communication with a UE115 on multiple cells or carriers, a feature which may be referred to ascarrier aggregation or multi-carrier operation. A UE 115 may beconfigured with multiple downlink component carriers and one or moreuplink component carriers according to a carrier aggregationconfiguration. Carrier aggregation may be used with both FDD and TDDcomponent carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including wider carrier or frequency channel bandwidth, shortersymbol duration, shorter TTI duration, or modified control channelconfiguration. In certain instances, an eCC may be associated with acarrier aggregation configuration or a dual connectivity configuration(e.g., when multiple serving cells have a suboptimal or non-idealbackhaul link). An eCC may also be configured for use in unlicensedspectrum or shared spectrum (e.g., where more than one operator isallowed to use the spectrum, such as NR-shared spectrum (NR-SS)). An eCCcharacterized by wide carrier bandwidth may include one or more segmentsthat may be utilized by UEs 115 that are not capable of monitoring thewhole carrier bandwidth or are otherwise configured to use a limitedcarrier bandwidth (e.g., to conserve power).

In additional cases, an eCC may utilize a different symbol duration thanother component carriers, which may include use of a reduced symbolduration as compared with symbol durations of the other componentcarriers. A shorter symbol duration may be associated with increasedspacing between adjacent subcarriers. A device, such as a UE 115 or basestation 105, utilizing eCCs may transmit wideband signals (e.g.,according to frequency channel or carrier bandwidths of 20, 40, 60, 80MHz, etc.) at reduced symbol durations (e.g., 16.67 microseconds). A TTIin eCC may consist of one or multiple symbol periods. In some cases, theTTI duration (that is, the number of symbol periods in a TTI) may bevariable.

Wireless communications system 100 may be an NR system that may utilizeany combination of licensed, shared, and unlicensed spectrum bands,among others. The flexibility of eCC symbol duration and subcarrierspacing may allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossthe frequency domain) and horizontal (e.g., across the time domain)sharing of resources.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE115, which may be one of the base station and one of the UEs in FIG. 1 .At base station 105, a transmit processor 220 may receive data from adata source 212 and control information from a controller/processor 240.The control information may be for the PBCH, PCFICH, PHICH, PDCCH,EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmitprocessor 220 may process (e.g., encode and symbol map) the data andcontrol information to obtain data symbols and control symbols,respectively. The transmit processor 220 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 230 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators/demodulators 232 athrough 232 t. Each modulator/demodulator 232 may process a respectiveoutput symbol stream (e.g., for OFDM, etc.) to obtain an output samplestream. Each modulator/demodulator 232 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. Downlink signals frommodulators/demodulators 232 a through 232 t may be transmitted via theantennas 234 a through 234 t, respectively.

At UE 115, the antennas 252 a through 252 r may receive the downlinksignals from the base station 105 and may provide received signals tothe modulators/demodulators 254 a through 254 r, respectively. Eachmodulator/demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a respective received signal to obtain inputsamples. Each modulator/demodulator 254 may further process the inputsamples (e.g., for OFDM, etc.) to obtain received symbols. A MIMOdetector 256 may obtain received symbols from all themodulators/demodulators 254 a through 254 r, perform MIMO detection onthe received symbols if applicable, and provide detected symbols. Areceive processor 258 may process (e.g., demodulate, deinterleave, anddecode) the detected symbols, provide decoded data for the UE 115 to adata sink 260, and provide decoded control information to acontroller/processor 280.

On the uplink, at the UE 115, a transmit processor 264 may receive andprocess data (e.g., for the PUSCH) from a data source 262 and controlinformation (e.g., for the PUCCH) from the controller/processor 280. Thetransmit processor 264 may also generate reference symbols for areference signal. The symbols from the transmit processor 264 may beprecoded by a TX MIMO processor 266 if applicable, further processed bythe modulators/demodulators 254 a through 254 r (e.g., for SC-FDM,etc.), and transmitted to the base station 105. At the base station 105,the uplink signals from the UE 115 may be received by the antennas 234,processed by the modulators/demodulators 232, detected by a MIMOdetector 236 if applicable, and further processed by a receive processor238 to obtain decoded data and control information sent by the UE 115.The processor 238 may provide the decoded data to a data sink 239 andthe decoded control information to the controller/processor 240.

The controllers/processors 240 and 280 may direct the operation at thebase station 105 and the UE 115, respectively. The controller/processor240 and/or other processors and modules at the base station 105 mayperform or direct the execution of various processes for the techniquesdescribed herein. The controllers/processor 280 and/or other processorsand modules at the UE 115 may also perform or direct the execution ofthe functional blocks illustrated in FIGS. 3A and 3B, and/or otherprocesses for the techniques described herein. The memories 242 and 282may store data and program codes for the base station 105 and the UE115, respectively. A scheduler 244 may schedule UEs for datatransmission on the downlink and/or uplink.

In NR or NR-U operations, a scheduling request (SR) may be periodicallyconfigured via uplink control signaling, (e.g., PUCCH) to give the UE anopportunity to request resources for uplink transmissions. However, inNR operations defined in 3GPP Release 15 (Rel. 15), the SR can becancelled via signaling such as a slot format indication (SFI), downlinkcontrol information (DCI). An SR may be cancelled when the SFI indicatesthe SR symbols to configured as either flexible or downlink symbols. AnSF may also be cancelled when the UE receives a downlink grant toreceive in the SR-configured symbols. In NR-U operations defined in 3GPPRelease 16 (Rel. 16), the SR can further be cancelled if the UE does nothave access to the shared communication channel, such as when the UEdetects an unsuccessful LBT procedure for accessing the shared channel.Additionally, when a DCI format 2_0 is configured but not detected bythe UE, the configured SR will be cancelled. If there is chance that theconfigured SR cannot be transmitted, there may be a negative impact tothe UE's uplink traffic transmission. When the UE cannot send an SR, theUE will not be granted uplink resources for the transmission.

In an effort to provide a UE with additional chances for transmittingSR, prior transmission technologies (e.g., MulteFire) have allowed theUE to send SR in the special subframe at the beginning of an uplinkburst in a given transmission opportunity. However, neither NR nor NR-Uoperations define a special subframe. Moreover, the more rigid structuredefined in the special subframe opportunity may not fit within the moreflexible nature of NR and NR-U operations. Accordingly, various aspectsof the present disclosure are directed to an on-demand or triggered SR,in which the UE is preconfigured with triggered SR resources fortriggered SR transmissions. Compatible UEs may further be configured tomonitor for a trigger signal, which triggers the UE to use suchtriggered SR resources for SR transmissions.

FIG. 3 is a block diagram illustrating example blocks executed by a UEto implement one aspect of the present disclosure. The example blockswill also be described with respect to UE 115 as illustrated in FIGS. 2and 6 . FIG. 6 is a block diagram illustrating UE 115 configuredaccording to one aspect of the present disclosure. UE 115 includes thestructure, hardware, and components as illustrated for UE 115 of FIG. 2. For example, UE 115 includes controller/processor 280, which operatesto execute logic or computer instructions stored in memory 282, as wellas controlling the components of UE 115 that provide the features andfunctionality of UE 115. UE 115, under control of controller/processor280, transmits and receives signals via wireless radios 600 a-r andantennas 252 a-r. Wireless radios 600 a-r includes various componentsand hardware, as illustrated in FIG. 2 for UE 115, includingmodulator/demodulators 254 a-r, MIMO detector 256, receive processor258, transmit processor 264, and TX MIMO processor 266.

At block 300, a UE receives a configuration message from a serving basestation, wherein the configuration message configures a transmissionresource for triggered SR transmission. The UE, such as UE 115, undercontrol of controller/processor 280, executes triggered SR logic 601,stored in memory 282. The functionality and actions enabled by executionof the code and instructions of triggered SR logic 601 (referred to asthe “execution environment” of triggered SR logic 601) provides for UE115 to recognize the control signaling that configure UE 115 withtriggered SR resources. UE 115 may then store the configured resourcesin memory 282 at T-SR resources 602. The triggered SR resources may beconfigured either as a fixed resource or pool of resources that UE 115may select, such as via a selection process, such as a selectionsequence, hashing procedure, or the like, that will be known to both UE115 and the serving base station.

At block 301, the UE monitors for a trigger signal triggeringtransmission of a triggered SR. UE 115 may further be configured for theon-demand or triggered SR procedure by the serving base station. Furtherwithin the execution environment of triggered SR logic 601, UE 115 wouldrecognize the configuration signaling, received via antennas 252 a-r andwireless radios 600 a-r, that identifies to UE 115 a bit field within aparticular control signal where a trigger signal would be located forconducting the triggered SR transmission. UE 115 monitors for theidentified bit field for the trigger signal.

At block 302, the UE transmits the triggered SR using the transmissionresource in response to detecting the trigger signal. For UE 115, whichis configured for on-demand or triggered SR operations within theexecution environment of triggered SR logic 601, when the trigger signalis detected in the identified bit field, UE 115 may then transmit atriggered SR in the preconfigured triggered SR resources. When UE 115detects data in data buffer 603, in memory 282, it may use the triggeredSR resource selected from T-SR resources for transmitting an SR toobtain an uplink grant for transmitting the data.

FIG. 3B is a block diagram illustrating example blocks executed by a UEto implement one aspect of the present disclosure. The example blockswill also be described with respect to base station 105 as illustratedin FIG. 2 . Base station 105 includes the structure, hardware, andcomponents as illustrated for UE 115 of FIG. 2 . For example, basestation includes controller/processor 240, which operates to executelogic or computer instructions stored in memory 242, as well ascontrolling the components of base station 105 that provide the featuresand functionality of base station 105. Base station 105, under controlof controller/processor 240, transmits and receives signals via variouscomponents and hardware, as illustrated in FIG. 2 , includingmodulator/demodulators 232 a-t, MIMO detector 236, receive processor238, transmit processor 220, and TX MIMO processor 230, and antennas 234a-t.

At block 310, a base station transmits a configuration message to one ormore served UEs, the configuration message configuring a transmissionresource for triggered SR transmission. The base station, such as basestation 105, may configure resources for UEs to perform triggered SRtransmissions and then sends the configuration message, via transmitprocessor 220, TX MIMO processor 230, modulator/demodulators 232 a-t,and antennas 234 a-t, under control of controller/processor 240. Basestation 105 sends this configuration message to one or more of the UEsthat it serves. The triggered SR resources may be configured either as afixed resource or pool of resources that a UE may select.

At block 311, the base station transmits a control signal including atrigger signal for the triggered SR transmission. Base station 105transmits the control message via transmit processor 220, TX MIMOprocessor 230, modulator/demodulators 232 a-t, and antennas 234 a-t,under control of controller/processor 240. The control message mayinclude messages, such as PDCCH or group common (GC)-PDCCH with a bitfield that the UEs would monitor, according to the configurationmessage, for the trigger signal. The bit field can provide a timingindication for SR transmissions.

At block 312, the base station receives the triggered SR transmissionfrom at least one served UE of the one or more served UEs using thetransmission resource. The configuration message, which configurestransmission resources for UEs to perform triggered SR transmissionsallow more opportunities for the UEs to send SR. Once the served UEsidentify a triggered SR opportunity, the UEs would transmit thetriggered SR, which are received at base station 105 using some of theconfigured transmission resources, via antennas 234 a-t,modulator/demodulators 232 a-t, MIMO detector 236, and receive processor238, under control of controller/processor 240.

FIG. 4 is a block diagram illustrating an NR-U network 40 having UEs 115a and 115 h-115 j in communication with base station 105 and configuredfor on-demand or triggered SR according to aspects of the presentdisclosure. UEs 115 a and 115 h-115 j communicate with base station 105via a shared communication channel. Transmission streams 400-403represent the communications over the shared communication channel fromUEs 115 a and 115 h-115 j, respectively. At 405, base station 105transmits a configuration message to UEs 115 a and 115 h-115 jconfiguring the UEs for on-demand or triggered SR operations. Theconfiguration message at 405 configures UEs 115 a and 115 h-115 j withthe identification of a bit field within a control message (e.g., PDCCH,group common (GC)-PDCCH, etc.) that would contain a trigger signal. Forexample, the configuration message at 405 from base station 105configures the UEs 115 a and 115 h-115 j with the radio networktemporary identifier (RNTI) for the GC-PDCCH, which search space the UEsare to search, and which bit field within the GC-PDCCH will contain theSR trigger signal. As illustrated, the same trigger bit can beconfigured for multiple UEs so they transmit the SRs together.

A configuration message at 405 may also configure the trigger SRresources for UEs 115 a and 115 h-115 j. The trigger SR resources may beconfigured as a fixed resource, as illustrated for triggered SRresources, T-SR 411, 413, 414, 418, 420, 421, 425, 427, 428, 432, 434,and 435. UEs 115 a and 115 h-115 j would then monitor for the bit fieldin the control message identified in the configuration message at 405.

Base station 105 transmits the control message at 406. The controlmessage at 406 may include, for example, the PDCCH or GC-PDCCH with thebit field that UEs 115 a and 115 h-115 j are monitoring for the triggersignal. In addition to the trigger signal, the bit field can provide atiming indication for SR transmission. Such a timing indication mayinclude offset 407, which may indicate a slot offset from the controlmessage (e.g., GC-PDCCH) at 406 to the trigger SR, T-SR 411. Forexample, offset 407 may be signaled in the form of a K2 offsetindication instead of a fixed offset from the control message at 406.

It should be noted that base station 105 may transmit the trigger signaldynamically in order to trigger UE 115 to use a next triggered SRresource when UE 115 has experienced some canceled scheduled SRoccasions. In additional or alternative aspects, base station 105 maysemi-persistently initiate UE 115 to begin using the triggered SRresources.

It should be noted that, in additional or alternative aspects of thepresent disclosure, other information can also be provided, within theconfiguration message at 405 or in the control message at 406.

Different options may be implemented to trigger a UE to actually use thetriggered SR resource for SR transmissions. With multiple UEs eachavailable to send such SR transmissions, there may be occasions wheretransmission collisions or congestion may occur with multiple UEs eachtrying to use the triggered SR resources for the SR transmissions. In afirst optional implementation, all UEs configured to monitor the bitfield in the control message are eligible for transmission if the bitfield indicates a trigger signal. For example, because each of UEs 115 aand 115 h-115 j have been configured for on-demand or triggered SRoperations at 405, each of UEs 115 a and 115 h-115 j are eligible to usethe preconfigured triggered SR resources for SR transmission. Thisoptional implementation may be useful for a case that the SR trigger isprovided as an additional opportunity for SR reporting. It may also bepossible that a UE is not configured with SR opportunities in thebeginning, so all SR opportunities are triggered.

In a second optional implementation, the UEs that are eligible for usingthe triggered SR resources for SR transmissions are the ones of UEs 115a and 115 h-115 j that are both configured for on-demand or triggered SRand have experienced cancelation of a preconfigured number of configuredSR occasions within a window, such as window 404. Base station 105 mayconfigured UEs 115 a and 115 h-115 j with the length of window 404 ineither the configuration message at 405 or the control message at 406.As illustrated, window 404 extends beyond the triggered SR resources,T-SR 411, 418, 425, and 432. Accordingly, a UE with an SR opportunitywithin window 404 in the future can transmit as well. UEs 115 a and 115h-115 j can assume the future SR opportunities will be cancelled, suchthat the later opportunities may be polled in the triggered SR resource,T-SR 411, 418, 425, and 432.

For example, where a threshold number of three canceled SR occasionswithin window 404 is set for performing triggered SR transmissions, asthe trigger signal is detected by UE 115 i, UE 115 i has onlyexperienced two canceled SR occasions at C-SRs 422 and 423. Because thewindow 404 extends beyond the triggered resource, T-SR 425, UE 115 i maycontinue to monitor configured SR occasions. Thus, as UE 115 iexperiences a third canceled configured SR occasion at C-SR 424 afterthe trigger signal at 406, it may then be eligible to use T-SR 425.

In a further example, UE 115 a is able to transmit SR at T-SR 411 and,therefore, assumes the next configured SR occasion within window 404 atC-SR 412 is canceled or actively unschedules the occasion at C-SR 412.UE 115 h detects failure of an LBT procedure for access to the sharedcommunication channel and, thus, cannot transmit SR at T-SR 418. In suchan instance, UE 115 h may be allowed to transmit SR at C-SR 419 withinwindow 404. Similar to UE 115 a, UE 115 i unschedules C-SR 426 aftersuccessfully transmitting SR at T-SR 425, and similar to UE 115 h, UE115 j does not have access to the shared channel and cannot send an SRat T-SR 432. However, UE 115 j also cannot successfully complete an LBTfor access to the shared channel for transmitting SR at C-SR 433.

According to the second optional implementation, before any of UEs 115 aand 115 h-115 j would attempt to transmit SR at the triggered SRresource, T-SR 411, 418, 425, and 432, each would determine whether theyhad experienced configured SR cancelations up to the preconfiguredthreshold number. This may be beneficial for the case where thetriggered SR resources are provided for compensating SR resources. Basestation 105 would have good knowledge of which of UEs 115 a and 115h-115 j experienced canceled configured SR occasions, such as byprevious SFI or DCI-based cancellations, or due to any of UEs 115 a or115 h-115 j being outside of an available channel occupancy time (COT),where such UE is not configured to transmitting SR outside of anavailable COT.

FIG. 5 is a block diagram illustrating an NR-U network 40 having UEs 115a and 115 h-115 j in communication with base station 105 and configuredfor on-demand or triggered SR according to aspects of the presentdisclosure. UEs 115 a and 115 h-115 i communicate with base station 105via a shared communication channel. Transmission streams 500-502represent the communications over the shared communication channel fromUEs 115 a and 115 h-115 i, respectively. At 504, base station 105transmits a configuration message to UEs 115 a and 115 h-115 iconfiguring the UEs for on-demand or triggered SR operations, asdescribed above with respect to FIG. 4 . The configuration message at504 configures UEs 115 a and 115 h-115 i with the identification of abit field within a control message (e.g., PDCCH, group common(GC)-PDCCH, etc.) that would contain a trigger signal.

A configuration message at 405 may also configure the triggered SRresources for UEs 115 a and 115 h-115 i. Instead of fixed resources, asdescribed in the aspect illustrated in FIG. 4 , the trigger SR resourcesof FIG. 5 are configured as a pool of multiple triggered SR resources,T-SR pool 507. T-SR pool 507 includes multiple candidate triggered SRresources that may be selected by UEs 115 a and 115 h-115 i fortriggered SR transmissions. It should be noted that, while T-SR pool 507includes identification of three resources, labeled A, B, and C, itshould be understood that T-SR pool 507 may include more than threecandidate resources. The labeled pool resources, A, B, C, are includedfor ease of description.

As illustrated in FIG. 5 , UEs 115 a and 115 h-115 i determine a numberof canceled configured SR occasions, C-SR, over window 503. The lengthof window 503 is configured before the triggered SR resource, T-SR pool507. Thus, the ones of UEs 115 a and 115 h-115 i that have experiencedcancelled configured SR occasions over a preconfigured threshold numbermay be eligible for using the triggered SR resources for SRtransmissions. Thus, in an example implementation where a UE would haveto experience two or more canceled configured SR occasions, UEs 115 hand 115 i would be eligible, while UE 115 a would not. In an exampleimplementation where a UE would have to experience one canceledconfigured SR occasion, each of UEs 115 a and 115 h-115 i would beeligible.

With the triggered SR resources defined as a pool of resources, T-SRpool 507, UEs 115 a and 115 h-115 i may use a preconfigured procedure toselect the resource for the triggered SR transmission from T-SR pool507. Such a preconfigured procedure would also be known to base station105. In one example implementation, the preconfigured procedure may be aselection pattern known to each of UEs 115 a and 115 h-115 i and basestation 105. In another example implementation, the preconfiguredprocedure may be a hash procedure known to each of UEs 115 a and 115h-115 i and base station 105.

At 505, base station 105 transmits the control message that includes thebit field for which UEs 115 a and 115 h-115 i are monitoring for atrigger signal. If such a trigger signal is detected in the controlmessage, UEs 115 a and 115 h-115 i may determine whether to actually useone of the triggered SR resources of T-SR pool 507 to transmit an SR. Asindicated above, the bit field may further include a offset, such asoffset 506, which identifies the offset from the control message at 506that UEs 115 a and 115 h-115 i may transmit on the triggered SRresource. As the trigger signal is detected and UEs 115 a and 115 h-115i determine to use triggered SR resource, each of UEs 115 a and 115h-115 i may performing the hashing sequence to select a resource fromT-SR pool 507. For example, UE 115 a may hash to resource A of the firstinstance of T-SR pool 507 on transmission stream 500, and to resource Cof the second instance of T-SR pool 507. UE 115 h may hash to resource Cof the first instance of T-SR pool 507 on transmission stream 501, andto resource A of the second instance of T-SR pool 507. UE 115 i may alsocollide with UE 115 h by hashing to resource C of the first instance ofT-SR pool 507 on transmission stream 502. UE 115 i determines that it isnot eligible to use the triggered SR resource of the second instance ofT-SR pool 507 and does not perform the hashing.

As illustrated with respect to UEs 115 h and 115 i, there is a chancefor multiple UEs to hash to the same resource. In order to address suchcollision, a hashing seed or hashing control may be included in the bitfield with SR trigger signal to affect the UE's hashing rule. Such ahashing seed or control provided to UEs 115 h and 115 i may allow eachsuch UE to hash to a different resource of T-SR pool 507. In otherwords, the hashing results will be different under different hashingseed, so it is likely, by choosing the proper hashing seed, the numberof collision events can be reduced or removed.

In order to control congestion of UEs attempting to transmit SR usingthe triggered SR resources, additional aspects may include additionalfactors for each eligible UE to consider before transmitting SR usingthe triggered SR resources, whether fixed (FIG. 4 ) or pooled (FIG. 5 ).According to one example aspect, each of UEs 115 a and 115 h-115 igenerate a random variable to compare against a preconfigured thresholdvalue. When the random variable meets the threshold value, the UE cantransmit using the triggered SR resources, while, when the randomvariable fails to meet the threshold, the UE cannot transmit using thetriggered SR resources. The random variable may be generated as apseudo-random value, such that both base station 105 and UEs 115 a and115 h-115 i would be able to arrive at the same pseudo-random value. Therandom variable procedure may further be useful when there are too manyUEs eligible for the triggered SR resource pool to transmit withoutcausing multiple collisions.

According to another example aspect, it may not be urgent for a UE totransmit SR quickly, such that the UE can afford a few cancellations ofSR occasions. Thus, after determining their eligibility for accessingT-SR pool 507 for SR transmissions, each of UEs 115 a and 115 h-115 ithen determine whether the number of configured SR opportunitycancelations it has experienced. This calculation of canceled configuredSR occasions is different than the determination of the number ofcanceled configured SR occasions to determine eligibility according tothe previously-described example aspect. For example, the number may bepredetermined at two or more cancelations. Accordingly, after each ofUEs 115 a and 115 h-115 i have determined their eligibility to accessT-SR pool 507, UE 115 h and 115 i each determine that they haveexperienced two cancelations (C-SR 512-513 and 516-517) and, thus, mayselect a resource of T-SR pool 507 for triggered SR transmissions.However, UE 115 a determines that it has only experienced onecancelation at C-SR 509 and one successful SR transmission at C-SR 508.Therefore, UE 115 a determines that it will not select a resource fromT-SR pool 507 to attempt a triggered SR transmission. Instead, UE 115 amay attempt SR transmission at C-SR 510.

According to another example aspect, UEs 115 a and 115 h-115 i maydetermine whether to use triggered SR transmission according to thetransmission priority of the uplink transmission. The SR also hasdifferent priority depending on the associated logic channel. Thus, basestation 105 may trigger the SR based on the priority associated with thecorresponding UE. For example, UEs 115 a and 115 h-115 i may determinetheir transmission priority before selecting a resource from T-SR pool507. In one scenario, UE 115 a and 115 i may have a priority higher thana predefined level and, thus, may select a resource from T-SR pool 507for triggered SR transmission. The priority threshold can be RRCconfigured by base station 105 or may be included in the bit field ofthe control message for the SR trigger signal.

In each of the example aspects for managing congestion of the triggeredSR resources, after UEs 115 a and 115 h-115 i detect the trigger signalin the control message at 505, UEs 115 a and 115 h-115 i may unscheduleor cancel the current configured SR occasions, C-SR 510, 511, 514, 515,518, and 519, after window 503. However, where any of UEs 115 a and 115h-115 i determine it should not use triggered SR resources, the UE mayuse the unscheduled configured SR resource for SR transmissions.

When transmitting the triggered SR according to the various aspects ofthe present disclosure. The SR transmission will not be multiplexed withany other feedback, such as channel state information (CSI), hybridautomatic receive request (HARQ) acknowledgement information, and thelike. In this way, the uplink format for the control transmission (e.g.,PUCCH) will be the same for all UEs and, thus, easier to plan theresources. For example, PUCCH format 0 or 1 may be used to carry one bitonly for SR.

Additionally, a triggered SR resource pool, such as T-SR pool 507 isconfigured as a time/frequency domain PUCCH resource with either acyclic shift or a pair of cyclic shifts. In one optional implementationwith a single cyclic shift, the UE, such as one or more of UEs 115 a and115 h-115 i would only transmit when a request for resources is beingmade with the SR transmission. In a second optional implementation witha pair of cyclic shifts, the UE, such as one or more of UEs 115 a and115 h-115 i can transmit a positive SR, when resources are requested foruplink transmission, or a negative SR, when the UE does not have data inthe buffer for uplink transmission and it, therefore, not requestingtransmission resources.

In current NR behavior, if a UE is not configured with SR resources, theUE will use physical random access channel (PRACH) to request uplinkresources. Referring back to FIG. 4 , where a UE, such as UE 115 j, isconfigured with triggered SR resources (e.g., T-SR 432, 434, and 435, UE115 j may fall back to use PRACH 436, when there have been no successfulopportunities for SR transmission over threshold period 437. Asexperienced by UE 115 j, each SR occasion has either been canceled orunsuccessful, C-SR 429-431 and T-SR 432, 434, and 435, or unscheduled,C-SR 433. The threshold length of threshold period 437 can be RRCconfigured or hard coded.

It should be noted that such fall back to PRACH after a preconfiguredthreshold can be further extended even if triggered SR resources are notconfigured. If configured SR opportunities have been cancelled orunsuccessful for such a fall back threshold, the UE may fall back tousing PRACH for request of resources for transmission.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

The functional blocks and modules in FIGS. 3A and 3B may compriseprocessors, electronics devices, hardware devices, electronicscomponents, logical circuits, memories, software codes, firmware codes,etc., or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure. Skilled artisans will also readilyrecognize that the order or combination of components, methods, orinteractions that are described herein are merely examples and that thecomponents, methods, or interactions of the various aspects of thepresent disclosure may be combined or performed in ways other than thoseillustrated and described herein.

The various aspects of the present disclosure may be implemented in manydifferent ways, including methods, processes, non-transitorycomputer-readable medium having program code recorded thereon, apparatushaving one or more processors with configurations and instructions forperforming the described features and functionality, and the like. Afirst aspect configured for wireless communication includes receiving,by a UE, a configuration message from a serving base station, whereinthe configuration message configures a transmission resource fortriggered SR transmission, monitoring, by the UE, for a trigger signaltriggering transmission of a triggered SR, and transmitting, by the UE,the triggered SR using the transmission resource in response todetecting the trigger signal.

A second aspect, alone or in combination with a first aspect, furtherincluding receiving, at the UE, a triggered SR configuration messagethat identifies a bit field within a control signal of the serving basestation for the monitoring for the trigger signal.

A third aspect, alone or in combination with the second aspect, whereinthe trigger signal includes a timing indication for the triggered SRtransmission.

A fourth aspect, alone or in combination with the third aspect, whereinthe timing indication includes one of a fixed transmission time; or aslot offset from the trigger signal.

A fifth aspect, alone or in combination with the second aspect, furtherincluding: receiving, by the UE, a window length parameter, wherein thewindow length parameter is received in one of: the triggered SRconfiguration message or the bit field for the trigger signal; anddetermining, by the UE, cancellation of one or more configured SRopportunities within a window length determined by the window lengthparameter, wherein the transmitting the triggered SR is further inresponse to determination of the cancellation of the one or moreconfigured SR opportunities within the window length.

A sixth aspect, alone or in combination with the fifth aspect, whereinthe window length is positioned one of: prior to transmission of thetriggered SR; or over a time including at least one future configured SRtransmission opportunity.

A seventh aspect, alone or in combination with the sixth aspect, furtherincluding: canceling the at least one future configured SR transmissionopportunity within the window length.

An eighth aspect, alone or in combination with the second aspect,wherein the transmission resource includes one of: a fixed resource forthe triggered SR transmission; or a selected resource from a pool oftransmission resources.

A ninth aspect, alone or in combination with the eighth aspect, furtherincluding: selecting, by the UE, the transmission resource from the poolof transmission resources using a hashing rule know to the UE and theserving base station.

A tenth aspect, alone or in combination with the ninth aspect, furtherincluding: receiving, by the UE, a hashing seed within the bit field,wherein the UE uses the hashing seed with the hashing rule for theselecting the transmission resource.

An eleventh aspect, alone or in combination with the eighth aspect,wherein each resource of the pool of transmission resources isconfigured with a time-frequency domain resource and one of: a singlecyclic shift or a pair of cyclic shifts.

A twelfth aspect, alone or in combination with the eleventh aspect,wherein, when the transmission resource is configured with the singlecyclic shift, the transmitting includes: transmitting a positive SR inthe triggered SR, in response to a request for scheduling uplinktransmission; and refraining from transmission of the triggered SR for anegative SR, in response to indicating no data for uplink transmission.

A thirteenth aspect, alone or in combination with the eleventh aspect,wherein, when the transmission resource is configured with the pair ofcyclic shifts, the transmitting includes: transmitting a positive SR inthe triggered SR, in response to a request for scheduling uplinktransmission; and transmitting a negative SR in the triggered SR, inresponse to indicating no data for uplink transmission.

A fourteenth aspect, alone or in combination with the second aspect,further including: generating, by the UE, a pseudo-random variable knownto the UE and the serving base station; comparing, by the UE, thepseudo-random variable to a preconfigured threshold, wherein thetransmitting is conducted in response to the pseudo-random variablefalling within the preconfigured threshold; and refraining, by the UE,from transmission of the triggered SR in response to the pseudo-randomvariable exceeding the preconfigured threshold.

A fifteenth aspect, alone or in combination with the second aspect,further including: determining, by the UE, a total number of cancelledconfigured SR transmissions that have been canceled over a predefinedperiod, wherein the transmitting is conducted in response to the totalnumber of cancelled configured SR transmissions exceeds a predeterminedthreshold; and refraining, by the UE, from transmission of the triggeredSR in response to the total number of cancelled configured SRtransmissions is less than the predetermined threshold.

A sixteenth aspect, alone or in combination with the second aspect,further including: comparing, by the UE, a transmission priorityassociated with a SR to a predetermined priority threshold, wherein thetransmitting is conducted in response to the transmission priorityexceeding the predetermined priority threshold; and refraining, by theUE, from transmission of the triggered SR in response to thetransmission priority falling below the predetermined prioritythreshold.

A seventeenth aspect, alone or in combination with the sixteenth aspect,further including: receiving, by the UE, the predetermined prioritythreshold via one of: a RRC configuration message or the bit field.

An eighteenth aspect, alone or in combination with the second aspect,wherein the transmitting includes: transmitting the triggered SR withoutother CSI and acknowledgement signals multiplexed therewith.

A nineteenth aspect, alone or in combination with the first aspect,further including: determining, by the UE, availability of transmissionof the triggered SR on the transmission resource, wherein thetransmitting occurs in response to a determination of transmissionavailability; and refraining, by the UE, from transmission of thetriggered SR in response to a determination of transmissionunavailability.

A twentieth aspect, alone or in combination with the nineteenth aspect,further including: determining, by the UE, no successful SRtransmissions over a predefined window of time; and performing, by theUE, a random access request procedure for an uplink transmission grant,in response to the determining the no successful SR transmissions.

A twenty-first aspect, alone or in combination with the twentiethaspect, wherein the predefined window of time is one of: precoded intothe UE; or received by the UE via control signaling from the servingbase station.

A twenty-second aspect including any combination of the first throughthe twenty-first aspects.

The various aspects of the present disclosure may be implemented in manydifferent ways, including methods, processes, non-transitorycomputer-readable medium having program code recorded thereon, apparatushaving one or more processors with configurations and instructions forperforming the described features and functionality, and the like. Atwenty-third aspect configured for wireless communication by a networkentity includes transmitting a configuration message to one or moreserved UEs, the configuration message configuring a transmissionresource for triggered SR transmission, transmitting a control signalincluding a trigger signal for the triggered SR transmission, andreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.

In a twenty-fourth aspect, alone or in combination with the twenty-thirdaspect, further including transmitting a triggered SR configurationmessage that identifies a bit field within the control signal for theone or more served UEs to monitor for the trigger signal.

In a twenty-fifth aspect, alone or in combination with one or more ofthe twenty-third aspect or the twenty-fourth aspect, wherein the triggersignal includes a timing indication for the triggered SR transmission.

In a twenty-sixth aspect, alone or in combination with one or more ofthe twenty-third aspect through the twenty-fifth aspect, wherein thetiming indication includes one of: a fixed transmission time; or a slotoffset from the trigger signal.

In a twenty-seventh aspect, alone or in combination with one or more ofthe twenty-third aspect through the twenty sixth aspect, furtherincluding transmitting a window length parameter in one of: thetriggered SR configuration message or the bit field for the triggersignal.

In a twenty-eighth aspect, alone or in combination with one or more ofthe twenty-third aspect through the twenty-seventh aspect, wherein thewindow length parameter is positioned one of: prior to transmission ofthe triggered SR; or over a time including at least one futureconfigured SR transmission opportunity.

In a twenty-ninth aspect, alone or in combination with one or more ofthe twenty-third aspect through the twenty-eighth aspect, wherein thetransmission resource includes one of: a fixed resource for thetriggered SR transmission; or a selected resource from a pool oftransmission resources.

In a thirtieth aspect, alone or in combination with one or more of thetwenty-third aspect through the twenty-ninth aspect, further includingtransmitting a hashing seed within the bit field, the hashing seed to beused by a UE of the one or more served UEs to select the transmissionresource.

In a thirty-first aspect, alone or in combination with one or more ofthe twenty-third aspect through the thirtieth aspect, wherein eachresource of the pool of transmission resources is configured with atime-frequency domain resource and one of: a single cyclic shift or apair of cyclic shifts.

In a thirty-second aspect, alone or in combination with one or more ofthe twenty-third aspect through the thirty-first aspect, furtherincluding transmitting a predetermined priority threshold to the one ormore served UEs via one of: a RRC configuration message or the bitfield, the predetermined priority threshold identifying a prioritythreshold for an SR transmission.

In a thirty-third aspect, alone or in combination with one or more ofthe twenty-third aspect through the thirty-second aspect, wherein thereceiving includes receiving the triggered SR without other CSI andacknowledgement signals multiplexed therewith.

In a thirty-fourth aspect, alone or in combination with one or more ofthe twenty-third aspect through the thirty-third aspect, furtherincluding transmitting control signaling including a predefined windowof time to the one or more served UEs, the predefined window of timedefining a threshold for the one or more served UEs to fall back toPRACH operation for SR transmissions.

A thirty-fifth aspect includes an apparatus for wireless communicationat a base station that includes at least one memory and at least oneprocessor coupled with the at least one memory. The at least oneprocessor is operable to cause the base station to transmit aconfiguration message to one or more served UEs, the configurationmessage configuring a transmission resource for triggered SRtransmission, transmit a control signal including a trigger signal forthe triggered SR transmission, and receive the triggered SR transmissionfrom at least one served UEs of the one or more served UEs using thetransmission resource.

In a thirty-sixth aspect, alone or in combination with the thirty-fifthaspect, further including the at least one processor operable to causethe UE to transmit a triggered SR configuration message that identifiesa bit field within the control signal for the one or more served UEs tomonitor for the trigger signal.

In a thirty-seventh aspect, alone or in combination with one or more ofthe thirty fifth aspect or the thirty-sixth aspect, wherein the triggersignal includes a timing indication for the triggered SR transmission.

In a thirty-eighth aspect, alone or in combination with one or more ofthe thirty-fifth aspect through the thirty-seventh aspect, wherein thetiming indication includes one of: a fixed transmission time; or a slotoffset from the trigger signal.

In a thirty-ninth aspect, alone or in combination with one or more ofthe thirty-fifth aspect through the thirty-eighth aspect, furtherincluding the at least one processor operable to cause the UE totransmit a window length parameter in one of: the triggered SRconfiguration message or the bit field for the trigger signal.

In a fortieth aspect, alone or in combination with one or more of thethirty-fifth aspect through the thirty-ninth aspect, wherein the windowlength parameter is positioned one of: prior to transmission of thetriggered SR; or over a time including at least one future configured SRtransmission opportunity.

In a forty-first aspect, alone or in combination with one or more of thethirty-fifth aspect through the fortieth aspect, wherein thetransmission resource includes one of: a fixed resource for thetriggered SR transmission; or a selected resource from a pool oftransmission resources.

In a forty-second aspect, alone or in combination with one or more ofthe thirty-fifth aspect through the forty-first aspect, furtherincluding the at least one processor operable to cause the UE totransmit a hashing seed within the bit field, the hashing seed to beused by a UE of the one or more served UEs to select the transmissionresource.

In a forty-third aspect, alone or in combination with one or more of thethirty-fifth aspect through the forty-second aspect, wherein eachresource of the pool of transmission resources is configured with atime-frequency domain resource and one of: a single cyclic shift or apair of cyclic shifts.

In a forty-fourth aspect, alone or in combination with one or more ofthe thirty-fifth aspect through the forty-third aspect, furtherincluding the at least one processor operable to cause the UE totransmit a predetermined priority threshold to the one or more servedUEs via one of: a RRC configuration message or the bit field, thepredetermined priority threshold identifying a priority threshold for anSR transmission.

In a forty-fifth aspect, alone or in combination with one or more of thethirty-fifth aspect through the forty-fourth aspect, wherein the atleast one processor operable to cause the UE to receive is furtheroperable to cause the UE to receive the triggered SR without other CSIand acknowledgement signals multiplexed therewith.

In a forty-sixth aspect, alone or in combination with one or more of thethirty-fifth aspect through the forty-fifth aspect, further includingthe at least one processor operable to cause the UE to transmit controlsignaling including a predefined window of time to the one or moreserved UEs, the predefined window of time defining a threshold for theone or more served UEs to fall back to PRACH operation for SRtransmissions.

A forty-seventh aspect may include an apparatus configured for wirelesscommunication by a base station including means for transmitting aconfiguration message to one or more served UEs, the configurationmessage configuring a transmission resource for triggered SRtransmission; means for transmitting a control signal including atrigger signal for the triggered SR transmission; and means forreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.

In a forty-eighth aspect, alone or in combination with the forty-seventhaspect, further including means for transmitting a triggered SRconfiguration message that identifies a bit field within the controlsignal for the one or more served UEs to monitor for the trigger signal.

In a forty-ninth aspect, alone or in combination with one or more of theforty-seventh aspect or the forty-eighth aspect, wherein the triggersignal includes a timing indication for the triggered SR transmission.

In a fiftieth aspect, alone or in combination with one or more of theforty-seventh aspect through the forty-ninth aspect, wherein the timingindication includes one of: a fixed transmission time; or a slot offsetfrom the trigger signal.

In a fifty-first aspect, alone or in combination with one or more of theforty-seventh aspect through the fiftieth aspect, further including:means for transmitting a window length parameter in one of: thetriggered SR configuration message or the bit field for the triggersignal.

In a fifty-second aspect, alone or in combination with one or more ofthe forty-seventh aspect through the fifty-first aspect, wherein thewindow length parameter is positioned one of: prior to transmission ofthe triggered SR; or over a time including at least one futureconfigured SR transmission opportunity.

In a fifty-third aspect, alone or in combination with one or more of theforty-seventh aspect through the fifty-second aspect, wherein thetransmission resource includes one of a fixed resource for the triggeredSR transmission; or a selected resource from a pool of transmissionresources.

In a fifty-fourth aspect, alone or in combination with one or more ofthe forty-seventh aspect through the fifty-third aspect, furtherincluding means for transmitting a hashing seed within the bit field,the hashing seed to be used by a UE of the one or more served UEs toselect the transmission resource.

In a fifty-fifth aspect, alone or in combination with one or more of theforty-seventh aspect through the fifty-fourth aspect, wherein eachresource of the pool of transmission resources is configured with atime-frequency domain resource and one of: a single cyclic shift or apair of cyclic shifts.

In a fifty-sixth aspect, alone or in combination with one or more of theforty-seventh aspect through the fifty-fifth aspect, further includingmeans for transmitting a predetermined priority threshold to the one ormore served UEs via one of: a RRC configuration message or the bitfield, the predetermined priority threshold identifying a prioritythreshold for an SR transmission.

In a fifty-seventh aspect, alone or in combination with one or more ofthe forty-seventh aspect through the fifty-sixth aspect, wherein themeans for receiving includes means for receiving the triggered SRwithout other CSI and acknowledgement signals multiplexed therewith.

In a fifty-eighth aspect, alone or in combination with one or more ofthe forty-seventh aspect through the fifty-seventy aspect, furtherincluding means for transmitting control signaling including apredefined window of time to the one or more served UEs, the predefinedwindow of time defining a threshold for the one or more served UEs tofall back to PRACH operation for SR transmissions.

A fifty-ninth aspect may include a non-transitory computer-readablemedium storing instructions on a base station. When executed by aprocessor, the instructions cause the processor to perform operationscomprising transmitting a configuration message to one or more servedUEs, the configuration message configuring a transmission resource fortriggered SR transmission, transmitting a control signal including atrigger signal for the triggered SR transmission; and receiving thetriggered SR transmission from at least one served UEs of the one ormore served UEs using the transmission resource.

In a sixtieth aspect, alone or in combination with the fifty-ninthaspect, further including instructions that, when executed by theprocessor, cause the processor to perform operations comprisingtransmitting a triggered SR configuration message that identifies a bitfield within the control signal for the one or more served UEs tomonitor for the trigger signal.

In a sixty-first aspect, alone or in combination with one or more of thefifty-ninth aspect or the sixtieth aspect, wherein the trigger signalincludes a timing indication for the triggered SR transmission.

In a sixty-second aspect, alone or in combination with one or more ofthe fifty-ninth aspect through the sixty-first aspect, wherein thetiming indication includes one of a fixed transmission time; or a slotoffset from the trigger signal.

In a sixty-third aspect, alone or in combination with one or more of thefifty-ninth aspect through the sixty-second aspect, further includinginstructions that, when executed by the processor, cause the processorto perform operations comprising: transmitting a window length parameterin one of: the triggered SR configuration message or the bit field forthe trigger signal.

In a sixty-fourth aspect, alone or in combination with one or more ofthe fifty-ninth aspect through the sixty-third aspect, wherein thewindow length parameter is positioned one of: prior to transmission ofthe triggered SR; or over a time including at least one futureconfigured SR transmission opportunity.

In a sixty-fifth aspect, alone or in combination with one or more of thefifty-ninth aspect through the sixty-fourth aspect, wherein thetransmission resource includes one of: a fixed resource for thetriggered SR transmission; or a selected resource from a pool oftransmission resources.

In a sixty-sixth aspect, alone or in combination with one or more of thefifty-ninth aspect through the sixty-fifth aspect, further includinginstructions that, when executed by the processor, cause the processorto perform operations comprising: transmitting a hashing seed within thebit field, the hashing seed to be used by a UE of the one or more servedUEs to select the transmission resource.

In a sixty-seventh aspect, alone or in combination with one or more ofthe fifty-ninth aspect through the sixty-sixth aspect, wherein eachresource of the pool of transmission resources is configured with atime-frequency domain resource and one of: a single cyclic shift or apair of cyclic shifts.

In a sixty-eighth aspect, alone or in combination with one or more ofthe fifty-ninth aspect through the sixty-seventh aspect, furtherincluding instructions that, when executed by the processor, cause theprocessor to perform operations comprising: transmitting a predeterminedpriority threshold to the one or more served UEs via one of: a RRCconfiguration message or the bit field, the predetermined prioritythreshold identifying a priority threshold for an SR transmission.

In a sixty-ninth aspect, alone or in combination with one or more of thefifty-ninth aspect through the sixty-eighth aspect, wherein theinstructions that cause the processor to perform operations comprisingreceiving includes instructions that cause the processor to performoperations comprising: receiving the triggered SR without other CSI andacknowledgement signals multiplexed therewith.

In a seventieth aspect, alone or in combination with one or more of thefifty-ninth aspect through the sixty-ninth aspect, further includinginstructions that, when executed by the processor, cause the processorto perform operations comprising: transmitting control signalingincluding a predefined window of time to the one or more served UEs, thepredefined window of time defining a threshold for the one or moreserved UEs to fall back to PRACH operation for SR transmissions.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another.Computer-readable storage media may be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that canbe used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, a connection may be properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, or digital subscriber line (DSL), thenthe coaxial cable, fiber optic cable, twisted pair, or DSL, are includedin the definition of medium. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

As used herein, including in the claims, the term “and/or,” when used ina list of two or more items, means that any one of the listed items canbe employed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C) or any of these in anycombination thereof.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication performed by abase station, the method comprising: transmitting a configurationmessage to one or more served user equipments (UEs), the configurationmessage configuring a transmission resource for triggered schedulingrequest (SR) transmission; transmitting a control signal including atrigger signal for the triggered SR transmission; and receiving thetriggered SR transmission from at least one served UEs of the one ormore served UEs using the transmission resource.
 2. The method of claim1, further including: transmitting a triggered SR configuration messagethat identifies a bit field within the control signal for the one ormore served UEs to monitor for the trigger signal.
 3. The method ofclaim 2, wherein the trigger signal includes a timing indication for thetriggered SR transmission.
 4. The method of claim 3, wherein the timingindication includes one of: a fixed transmission time; or a slot offsetfrom the trigger signal.
 5. The method of claim 2, further including:transmitting a window length parameter in one of: the triggered SRconfiguration message or the bit field for the trigger signal.
 6. Themethod of claim 5, wherein the window length parameter is positioned oneof: prior to transmission of the triggered SR; or over a time includingat least one future configured SR transmission opportunity.
 7. Themethod of claim 2, wherein the transmission resource includes one of: afixed resource for the triggered SR transmission; or a selected resourcefrom a pool of transmission resources.
 8. The method of claim 7, furtherincluding: transmitting a hashing seed within the bit field, the hashingseed to be used by a UE of the one or more served UEs to select thetransmission resource.
 9. The method of claim 7, wherein each resourceof the pool of transmission resources is configured with atime-frequency domain resource and one of: a single cyclic shift or apair of cyclic shifts.
 10. The method of claim 2, further including:transmitting a predetermined priority threshold to the one or moreserved UEs via one of: a radio resource control (RRC) configurationmessage or the bit field, the predetermined priority thresholdidentifying a priority threshold for an SR transmission.
 11. The methodof claim 2, wherein the receiving includes: receiving the triggered SRwithout other channel state information (CSI) and acknowledgementsignals multiplexed therewith.
 12. The method of claim 1, furtherincluding: transmitting control signaling including a predefined windowof time to the one or more served UEs, the predefined window of timedefining a threshold for the one or more served UEs to fall back tophysical random access channel (PRACH) operation for SR transmissions.13. An apparatus for wireless communication at a base stationcomprising: at least one memory; and at least one processor coupled withthe at least one memory, the at least one processor operable to causethe base station to: transmit a configuration message to one or moreserved user equipments (UEs), the configuration message configuring atransmission resource for triggered scheduling request (SR)transmission; transmit a control signal including a trigger signal forthe triggered SR transmission; and receive the triggered SR transmissionfrom at least one served UEs of the one or more served UEs using thetransmission resource.
 14. The apparatus of claim 13, further includingthe at least one processor operable to cause the UE to: transmit atriggered SR configuration message that identifies a bit field withinthe control signal for the one or more served UEs to monitor for thetrigger signal.
 15. The apparatus of claim 14, wherein the triggersignal includes a timing indication for the triggered SR transmission.16. The apparatus of claim 15, wherein the timing indication includesone of: a fixed transmission time; or a slot offset from the triggersignal.
 17. The apparatus of claim 14, further including the at leastone processor operable to cause the UE to: transmit a window lengthparameter in one of: the triggered SR configuration message or the bitfield for the trigger signal.
 18. The apparatus of claim 17, wherein thewindow length parameter is positioned one of: prior to transmission ofthe triggered SR; or over a time including at least one futureconfigured SR transmission opportunity.
 19. The apparatus of claim 14,wherein the transmission resource includes one of: a fixed resource forthe triggered SR transmission; or a selected resource from a pool oftransmission resources.
 20. The apparatus of claim 19, further includingthe at least one processor operable to cause the UE to: transmit ahashing seed within the bit field, the hashing seed to be used by a UEof the one or more served UEs to select the transmission resource. 21.The apparatus of claim 19, wherein each resource of the pool oftransmission resources is configured with a time-frequency domainresource and one of: a single cyclic shift or a pair of cyclic shifts.22. The apparatus of claim 14, further including the at least oneprocessor operable to cause the UE to: transmit a predetermined prioritythreshold to the one or more served UEs via one of: a radio resourcecontrol (RRC) configuration message or the bit field, the predeterminedpriority threshold identifying a priority threshold for an SRtransmission.
 23. The apparatus of claim 14, wherein the at least oneprocessor operable to cause the UE to receive is further operable tocause the UE to receive the triggered SR without other channel stateinformation (CSI) and acknowledgement signals multiplexed therewith. 24.The apparatus of claim 13, further including the at least one processoroperable to cause the UE to: transmit control signaling including apredefined window of time to the one or more served UEs, the predefinedwindow of time defining a threshold for the one or more served UEs tofall back to physical random access channel (PRACH) operation for SRtransmissions.
 25. An apparatus configured for wireless communication bya base station, the apparatus comprising: means for transmitting aconfiguration message to one or more served user equipments (UEs), theconfiguration message configuring a transmission resource for triggeredscheduling request (SR) transmission; means for transmitting a controlsignal including a trigger signal for the triggered SR transmission; andmeans for receiving the triggered SR transmission from at least oneserved UEs of the one or more served UEs using the transmissionresource.
 26. The apparatus of claim 25, further including: means fortransmitting a triggered SR configuration message that identifies a bitfield within the control signal for the one or more served UEs tomonitor for the trigger signal.
 27. The apparatus of claim 25, furtherincluding: means for transmitting control signaling including apredefined window of time to the one or more served UEs, the predefinedwindow of time defining a threshold for the one or more served UEs tofall back to physical random access channel (PRACH) operation for SRtransmissions.
 28. A non-transitory computer-readable medium storinginstructions on a base station that, when executed by a processor, causethe processor to perform operations comprising: transmitting aconfiguration message to one or more served user equipments (UEs), theconfiguration message configuring a transmission resource for triggeredscheduling request (SR) transmission; transmitting a control signalincluding a trigger signal for the triggered SR transmission; andreceiving the triggered SR transmission from at least one served UEs ofthe one or more served UEs using the transmission resource.
 29. Thenon-transitory computer-readable medium of claim 28, further includinginstructions that, when executed by the processor, cause the processorto perform operations comprising: transmitting a triggered SRconfiguration message that identifies a bit field within the controlsignal for the one or more served UEs to monitor for the trigger signal.30. The non-transitory computer-readable medium of claim 28, furtherincluding instructions that, when executed by the processor, cause theprocessor to perform operations comprising: transmitting controlsignaling including a predefined window of time to the one or moreserved UEs, the predefined window of time defining a threshold for theone or more served UEs to fall back to physical random access channel(PRACH) operation for SR transmissions.